The proposed research consists of combined genetic, physiological, and biochemical characterization of two transport systems in Neurospora: (1) the primary H ion-translocating ATPase of the plasma membrane, which functions to generate a large H electrochemical gradient; and (2) the H ion-dependent cotransport system for glucose, driven by the electrochemical gradient. ATPase and glucose transport mutants will be isolated and characterized, both physiologically and biochemically, in order to gain information about the molecular nature of the two transport processes and about the interactions between them. The results should contribute toward the understanding of ATP-dependent and cotransport mechanisms in eukaryotic cells generally.